1. Field of the Invention
The present invention relates generally to content delivery networks (CDNs), and more particularly, to media distribution in wireless communication networks.
2. Introduction
Limited storage of mobile devices is driving cloud services in which data and software are stored on the network. However, in wireless networks, limited wireless bandwidth, variable reliability of the communication channels, and mobility of the client devices discourages off-site data storage and produces significant challenges to media distribution.
The trend in 4G cellular is to make wireless client devices part of the network infrastructure by enabling them to communicate with each other and cooperate. For example, Cooperative MIMO, cooperative diversity, and ad-hoc peer-to-peer networking are being incorporated into the 4G wireless standards. These technologies expand coverage, extend range, and greatly increase bandwidth with minimal cost to wireless service providers. These technologies also provide a significant change to the network topology, as the conventional server-client topology is overlaid with some clients functioning as gateways and routers for other clients. As a result, the nature of media distribution needs to adapt to these new network topologies, especially when client devices generate content or relay content to other client devices.
For conventional media distribution over the Internet, providers of web content and applications typically deliver content from multiple servers at diverse locations in order to sustain a good end-user experience under high traffic loads. In a wireless network, mobile client devices may function as part of the CDN infrastructure. In some cases, mobile devices may be configured to function as “surrogate” origin servers (e.g., Edge Servers). In some cases, mobile client devices may generate content for localized data and software services, such as maps, weather, and traffic.
The extension of a CDN to a wireless ad-hoc network introduces challenges, including, among others, how to guarantee fault-tolerance as the location, availability, and link quality of each mobile terminal may be continuously changing; how to control how requests from end-users are distributed to each Edge Server; and how to guarantee high performance for end-users as network conditions change.
Accordingly, content delivery mechanisms need to adapt to highly variable network topologies and operating conditions in order to provide reliable media and data services. These and other needs in the field may be addressed by aspects of the present invention.